Explosive device countermeasures

ABSTRACT

A method and system for mitigating the effectiveness of IEDs are disclosed. The method can include detecting IEDs by sensing the presence of a non-linear electronic component of an IED. The presence of a non-linear electronic component of the IED can be detected by illuminating the device with a high power microwave signal containing a plurality of radio frequencies of electromagnetic radiation and receiving sum and/or difference frequency components that are produced by interaction of the illuminating signals with a non-linear IED component and subsequently re-radiated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims the benefit of U.S.patent application Ser. No. 11/393,386 filed Mar. 30, 2006 now U.S. Pat.No. 7,512,511 which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates generally to microwave electronics and,more particularly, to a method and system for detecting, locating,disabling and/or destroying Improvised Explosive Devices(IEDs), such asby using high power microwaves.

BACKGROUND

IEDs are used to injure or kill people and to damage vehicles and otherequipment. IEDs can be fashioned as roadside bombs that are detonatedwhen a vehicle passes nearby. IEDs can be elevated, such as by placingthem upon road signs or trees, so as to more effectively focus theirenergy on less armored portions of a vehicle. They can also be buried orpartially buried in order to make them more difficult to find.

IEDs are typically constructed from artillery or mortar shells. They canalso be made from explosives from a wide range of other sources. In manycases a detonator is attached so as to facilitate initiation of theexplosion. The detonator can be remotely controlled by cellulartelephone, radio, garage door opener or another electronic device. Byusing such electronic devices, the IED can be remotely detonated viaeither a manned trigger command or the use of automated fusing, e.g., bysensing the proximity of a vehicle.

The use of such IEDs by insurgents in Iraq has become commonplace.Indeed, it has been estimated that IEDs have, to date, accounted for asignificant fraction of the coalition deaths in Iraq. Consequently, itwould be beneficial to be able to detect, locate, disable and destroyIEDs such as those used by insurgents as roadside bombs in Iraq.

SUMMARY

Systems and methods are disclosed herein to provide for mitigating theeffectiveness of IEDs. One or more embodiments of the present inventioncomprise detection of an IED by sensing the presence of non-linearelectronic component(s) used in the IED's construction.

Detecting the presence of a non-linear electronic component of the IEDcan be accomplished by simultaneously illuminating the device withmultiple radio frequency (RF) electromagnetic signals and receiving acomplex RF signal return which contains sum and/or differencefrequencies and/or harmonics that are produced by interaction of theillumination signals with one or more of the IED's non-linearcomponents.

Illuminating the IED with RF electromagnetic radiation can beaccomplished by employing two narrow band RF signal sources.Alternatively, illuminating the IED with RF electromagnetic radiationcan employ three, four, five, six or more narrow band RF sources.Additionally, one or more of the illuminating RF sources may employwideband (WB) or ultra wideband (UWB) waveforms.

According to one embodiment of the present invention, the receivedcomplex signal re-radiated from the IED non-linear circuit(s),containing sum and/or difference frequencies, can be compared withstored signature data to confirm the detection of an IED. In thismanner, false positives (false indications that an IED has beendetected) are greatly reduced.

The location of the IED can be more precisely determined by illuminatingit using a narrow beamwidth transmit-receive microwave system whoseazimuth & elevation angles are well known versus time. Two or moreoptions are possible. A first option comprises transmitting two or morerelatively low frequency illuminating signals using fixed wide-beamwidthantennas. A higher frequency signal, i.e., the re-radiated sum frequencysignal with or without harmonic content, can be captured using anarrower beamwidth antenna operating at a higher, e.g., sum, frequency.

A second option comprises using synchronized scanning transmit/receiveantennas, wherein one set uses lower frequencies and another set useshigher frequencies. In the second option, the higher frequency transmitor receive antenna would be used as the primary source for determiningIED position. For either option, IED position knowledge can be enhancedby employing a combination of information including the slant range todetected IED using the multi-frequency round trip propagation time fromRF source to IED and the position of the illuminating platform obtainedfrom aircraft Global Positioning Satellite (GPS) information and/or thelocation of the terrain and its features/buildings obtained frompreviously stored location and/or signature data bases.

The IED can be disabled and/or destroyed by illuminating the device witha burst of comparatively higher power RF electromagnetic radiation. Thiscan be done using a narrower beam antenna coupled to the illuminating RFsource.

Thus, detecting the presence of non-linear electronic components of IEDscan be implemented by simultaneously illuminating the IED with two ormore transmitted RF signals and receiving resultant, identifiablesum/difference complex signals whose spectral signatures are know.Determining the location of the IED can make use of knowledge of theazimuth/elevation of the narrowest beamwidth transmit/receive antenna inconjunction with precise pointing angles of the narrow beamwidthantenna, the round trip propagation time aircraft-to-IED and the GPScoordinates of the illuminating aircraft/antenna. Disabling the IED canbe accomplished by illuminating the device with a burst of comparativelyhigher power microwave radiation using a comparatively narrow beam RFsource/antenna.

Even the comparatively lower power RF sources used for detection canemploy high power RF sources. These RF sources can merely be lower inpower than the RF sources used to disable or destroy the IED.

In one or more embodiments of the present invention, a system formitigating the effectiveness of IEDs can comprise one RF transmitterusing a plurality of radio frequencies radiated towards the implanteddevice such that the radio frequency return generated by a non-linearcomponent in the IED can contain complex recognizable signals and can bere-radiated back towards the illuminating aircraft. The counter-IEDsystem can also include a receiver for detecting the complex radiofrequency IED re-radiated return. The azimuth/elevation angles of thehigher frequency transmit/receive antenna can be used to locate the IEDin conjunction with other available aircraft/surface data, e.g.,aircraft GPS-determined location, terrain features/locations, etc.

Reception of the return, particularly if verified, is an indication thatan IED has been detected. Once such an indication that an IED has beendetected is obtained, then procedures can be implemented to render theIED ineffective.

According to one or more embodiments of the present invention, thesystem can employ a high power burst transmitter for rendering IEDsineffective. The high power burst transmitter can either disable ordestroy the IED. In either instance, the IED is rendered ineffective.

First and second transmit signals can use narrow band dual frequency,high power microwave illuminating transmitters. A second transmitter canuse narrow band, wideband (WB) or Ultra-Wideband (UWB) signals. Thehighest frequency transmit/receive antenna can have the narrowestbeamwidth and can be employed for IED location determination. The bursttransmitter can use a high power microwave (HPM) RF source and a narrowbeam transmit antenna.

The electromagnetic radiation used to detect, locate, disable and/ordestroy an IED can employ microwave electromagnetic radiation. Thefrequency content of the illuminating signal(s) used for detection,location and disablement or destruction respectively can be the same asone another or vary depending on desired functionality. For example, onepair of frequencies can be used for detection, a different pair can beused for location and one of the two frequencies used for location canbe used for disablement or destruction.

The scope of the invention is defined by the claims, which areincorporated into this section by reference. A more completeunderstanding of embodiments of the present invention is available tothose skilled in the art, as well as a realization of additionaladvantages thereof, by a consideration of the following detaileddescription of one or more embodiments. Reference can be made to theappended sheets of drawings that can first be described briefly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram illustrating the use of an IEDcountermeasures system in accordance with an exemplary embodiment of thepresent invention, wherein a wide beam, dual band, high power microwavetransmission is being broadcast to determine if an IED is present;

FIG. 2 shows a schematic diagram further illustrating the use of the IEDcountermeasures system of FIG. 1, wherein a higher frequency narrow beam(transmit/receive) antenna is being used to determine the location of anIED;

FIG. 3 shows a schematic diagram further illustrating the use of the IEDcountermeasures system of FIG. 1, wherein a narrow beam (such as a dualband narrow beam), high power, microwave burst is being transmitted todisable the IED;

FIG. 4 shows a block diagram illustrating use of the IED countermeasuressystem in accordance with an exemplary embodiment of the presentinvention;

FIG. 5 shows a block diagram illustrating an IED countermeasures systemin accordance with an exemplary embodiment of the present invention; and

FIG. 6 shows a flow chart illustrating operation of the IEDcountermeasures system defined in FIG. 5.

Embodiments of the present invention and their advantages are bestunderstood by referring to the detailed description that follows. Itshould be understood that like reference numerals are used to identifylike elements illustrated in one or more of the figures.

DETAILED DESCRIPTION

Contemporary electronic devices almost universally contain non-linearelectronic components. Examples of non-linear electronic componentsinclude diodes and transistors. Thus, the cellular telephones, radios,garage door openers, or other electronic devices used in the detonatorsof IEDs typically contain non-linear electronic components.

Such non-linear electronic components tend to function as inefficientradio frequency mixers when illuminated with two or more frequencies ofRF electromagnetic radiation. When the non-linear electronic componentsfunction as radio frequency mixers, they produce harmonics of theillumination frequencies, as well as sum and difference frequencies ofthe illumination frequencies. These harmonics, sum, and differencefrequencies are re-radiated and can be detected, e.g., received andrecognized. Generally, the sum and difference frequencies are of greateramplitude as compared to the harmonic frequencies, and thus are ofteneasier to detect.

As used herein, the term “detecting” can refer to the process ofdetermining that an IED is likely to be present in the general directionof illumination. The term “locating” can refer to more preciselydetermining where the IED has been placed. The term “disabling” canrefer to rendering the IED ineffective, such as by inhibiting itsability to be remotely detonated, i.e., dudding. The term “destroying”refers to exploding or partially exploding the IED.

According to one embodiment of the present invention, an IED can bedetected by illuminating an area using a multi-frequency, high powermicrowave (HPM) RF transmitter/antenna. When the IED is illuminated bythe multi-frequency HPM transmitter, sum and difference frequenciesand/or harmonics of the transmitted frequency are generated byinteracting with non-linear circuits included in the IED. Thesetransformed RF signals are re-radiated from the IED towards theilluminating HPM RF source and received through an antenna located onthe transmitting platform.

The receive antenna operates at the sum/difference frequency(s) andfeeds a receiver tuned to the transformed signal spectrum. Afterdetecting, the presence of an IED, its presence can be verified bydetermining if the characteristics of the re-radiated signalcorresponding to likely device signatures. After being verified, thelocation of the IED can be more precisely found by determining theazimuth and elevation angles of the highest frequency, e.g., narrowestbeam, transmit/receive antenna, as well as the round-trip propagationtime from the transmitter to the IED and back to a receiver. This givesthe location of the IED relative to the HPM platform. The location ofthe HPM system platform can be determined via the platforms GPScoordinates and/or the surface features of the terrain.

Further, according to one embodiment of the present invention, an IEDcan be disabled or destroyed by illuminating it with a burst of highpower microwave radiation. These processes are described, with referenceto the figures, in further detail below.

FIGS. 1-3 show the use of an IED countermeasures system (with multipleHPM system beam shapes) that has been installed in a rotorcraft 11 (inthe illustrated case, a tilt-wing aircraft is shown whose wings canrotate so as to provide operation like that of both an airplane and ahelicopter). Alternatively, a fixed wing aircraft, a helicopter, or anyother airborne vehicle can be used. However, a slower speed aircraft maybe more effective for this application since flying at a slower speedilluminates the IED for a longer period of time, thus resulting inimproved detection and destruction effects.

FIG. 1 shows rotorcraft 11 flying along a road 13 with mountains 15 inthe background. A convoy 14 is traveling upon road 13. As discussedabove, IEDs are commonly used as roadside bombs against such targets asa convoy 14.

The aircraft can serve as a platform for all components of theimprovised explosive countermeasures system of the present invention.That platform can contain all of the transmitters, receivers and otherequipments associated with the improvised explosive countermeasuressystem. It is possible that multiple aircraft can be used, with eachaircraft having a portion of the improvised explosive countermeasuressystem. The aircraft can be piloted, remotely controlled, or completelyautonomous, or any desired combination of piloted, remotely controlled,and completely autonomous aircraft can be used. A multiple aircraftcounter-IED system can be more complex than a single aircraftcounter-IED system, since both time of transmission/reception, angle oftransmission/reception and multiple aircraft location can need to besynchronized when more than one platform is employed.

By installing such countermeasures systems on a rotorcraft or otherairborne vehicle, both locating the IED and rendering it ineffective canbe performed from the same platform and at a safe range. Alternatively,IEDs can be located and/or rendered ineffective using countermeasuressystems installed in land based vehicles. Indeed, some countermeasuresfunctions can be performed from airborne platforms and othercountermeasures functions can be performed from land based platforms.

For example, the detection and location of IEDs can be performed fromairborne platforms and rendering ineffective can be performed from landbased platforms, or visa-versa. However, a more robust airbornedetection/disablement HPM system is preferred in order to maximize thesize of the territory searched and/or cleared of IEDs and so as tominimize damage from exploding ground embedded IEDs

Rotocraft 11 can broadcast multi-frequency high power microwaveradiation (such as via transmitter 150 and antenna 151 of FIG. 5) usinga relatively wide antenna beam (such as beam 12 of FIG. 1). The wideantenna beam is used to illuminate the suspected area where it isbelieved that one or more IEDs have been placed. The use of a widetransmit antenna beam increases the coverage of the broadcast microwaveradiation.

When wide beam 12 is incident upon an IED, multiple frequencies aremixed, albeit inefficiently, by one or more non-linear electroniccomponent of the device's electronic circuitry. The resulting harmonics,sum, and difference frequencies are re-radiated and can be detected bythe IED countermeasures system receiver of the present invention. Thatis, a microwave receiver (receiver 153 of FIG. 5) can be configured toreceive these re-radiated frequencies.

When such re-radiated frequencies are detected, the presence of an IEDcan be verified 154 (FIG. 5). Such verification can be performed byascertaining whether or not the re-radiated RF spectrum is consistentwith signatures of laboratory or field illuminated IEDs. For example,the re-radiated frequencies can be compared to known signatures of IEDsthat have been illuminated in laboratory and/or field tests. and thedata then stored in a computer database (such as per block 154 of FIG.5) for use on an airborne IED countermeasures platform.

In this manner, rotocraft 11 can illuminate a large area with amulti-frequency wide beam width (per block 151 of FIG. 5) high powermicrowave transmitter 150. For example, rotocraft 11 can fly along ahighway that is about to be traversed by a convoy 14 and can provide IEDdetection, location and IED-disabling countermeasures for convoy 14.

FIG. 2 shows the rotocraft 11 of FIG. 1 functioning as the IEDcountermeasures system. It is being used to better determine thelocation of an IED, after the IEDs presence has been verified. To betterdetermine the location of the IED, the higher frequency, narrow beamtransmitter/receiver antenna that processes the high power microwaveradiation can be used to more precisely determine the azimuth andelevation angles from the air platform to the ground emplaced IED. Theround-trip propagation time (transmitter to IED and back to receiverplatform) can be used to establish the slant range to the IED and GPSposition information can precisely locate the position of theilluminating air platform

As those skilled in the art can appreciate, the use of narrow beam 21allows position of the IED to be determined more precisely. This is truebecause when a return from the IED is received, the device must bewithin the smaller angular region covered by narrow beam 21 (as opposedto the larger area covered by wide beam 12). Thus, narrow beam 21 can beused to better locate the IED.

The Global Positioning System (GPS) and/or other positioning and/ornavigation systems can be used to project coordinates of the IED forsubsequent countermeasure processing or for future reference. Forexample, these coordinates can be used by the same rotocraft 11, anotherrotocraft, or an altogether different type of vehicle (such as a landbase vehicle, e.g., a truck) to render the IED ineffective.

FIG. 3 shows the rotocraft 11 of FIG. 1 as the IED countermeasuressystem thereof is being used to disable or destroy the IED. A narrowbeam, high power microwave burst 31 can be directed toward the IED afterits location has been established.

Either a single frequency or multiple frequencies can be transmitted inthe burst. Information from the verification process can be used todetermine the likelihood that the counter-IED system of the presentinvention can have the desired affect upon the IED. That is, thedatabase of known IED re-radiated signatures contains informationregarding the spectral content of the re-radiated signal from the IEDand thus can be used to establish the likelihood that the countermeasuresystem can be used to render the IED ineffective. The database cancontain information regarding the most effective frequency orfrequencies for use in the burst.

Burst 31 of high power microwave radiation can cause malfunctioning ofelectronic devices, such as cellular telephones, radios, or garage dooropeners that are used to detonate the IED. Such malfunctioning canresult in the inability to subsequently remotely control detonation(i.e. ‘duding’) of the IED, thereby rendering it ineffective. Suchmalfunctioning can also result in the premature detonation of the IED(that is, it can be detonated before convoy 14 is close enough to causeinjury, death, or damage).

FIG. 4 is a block diagram illustrating operation of the IEDcountermeasures system of one or more embodiments of the presentinvention. As shown, two high power microwave sources, 41 and 45, eachprovide a different center frequency F1 and F2 RF sources. These twosources can be a single or dual band, narrow band, wideband (WB) orUltra-Wideband (UWB) transmitters. Additionally, more than two sourcescan be used to provide more than two illuminating frequencies, ifdesired. The RF sources can be contained in a single multi-bandtransmitter or can be from separate transmitters.

HPM signal with center frequencies F1 and F1 are transmitted into theatmosphere via antennas or apertures 42 and 46, respectively. The HPMsignal operating on frequency F1 undergoes propagation 43 through theatmosphere and possibly some soil as well. The HPM signal operating onfrequency F2 likewise undergoes propagation 47 through the atmosphereand possibly some soil as well. Lower frequencies can be used fordetection, location, and disablement or destruction when soilpenetration is necessary (such as when the IED is buried or partiallyburied).

As indicated in blocks 44 and 48, frequencies F1 and F2 may encountershielding that interferes with their desired coupling to the intendedtarget, e.g., an IED. The use of high power microwave radiation enhancesthe likelihood of such coupling. Shielding can be part the IED or can beenvironmental, e.g., soil, water, rock, minerals, vegetation, or signage(such as metal road signs).

Remotely detonated IEDs can generally have an antenna by which itreceives a radio frequency detonation command. Generally, this antennacan be exposed and thus susceptible to coupling with transmittedfrequencies F1 and F2.

The result of coupling into the intended target 44 can produce mixingand frequency conversion 35 by non-linear components of the target. Suchnon-linear components can be diodes and transistors of a detonator thatis remotely controlled by radio frequency. This mixing can result in asum frequency of F1+F2 and a difference frequency of F1−F2 beinggenerated and re-radiated towards the illuminating air platform. It canalso result in various harmonic frequencies being produced andre-radiated. All of these resultant frequencies can, to some degree, bere-radiated. Typically, the sum frequency and/or the differencefrequency can be the frequency or frequencies used for IED detection.

Generally, the sum and difference frequencies can have higher amplitudesthan the harmonic frequencies. Also, it is often difficult to predictwhich harmonic frequencies can have the greatest amplitude; hence, thegeneration and use of laboratory/filed test signature data is invaluablefor later use onboard the countermeasure air platform. Therefore, inmany cases the sum and/or difference frequency signals can be used forIED detection, rather than any of the harmonic frequencies. However, theharmonic frequencies may be used instead of or in addition to the sumand/or difference frequencies. Indeed, in some instances the harmonicfrequencies may provide enhanced detection, verification, and/orlocation with respect to the sum and/or difference frequencies.

The mixing and frequency conversion of block 35 results in targetsusceptibility 36 to high power microwave radiation. The target, i.e.,the detonator of an IED, can be susceptible to detection and/or to beingdisabled or destroyed.

As indicated in block 37, radiation of the clock frequency of thedetonator of an IED or of any other radio frequencies of the device canbe detected remotely, such as from a flying aircraft or a land vehicle.Similarly, re-radiation of the harmonic, sum and/or differencesfrequencies can be detected. After detection and identification 38,electronic countermeasures can be employed to render the IEDineffective.

FIG. 5 is a block diagram illustrating an IED countermeasures systemaccording to one embodiment of the present invention. According to thisembodiment, a wide beam transmitter 150, a narrow beam receiver 153, andhigh power microwave burst transmitter 155 are used.

The wide beam transmitter 150 and antenna 151 define a high powermicrowave implementation in conjunction with the narrowband microwaveantenna 152 and receiver 153 provides the required transmit/receive IEDdetection capability. Similarly, narrow beam transmitter 155 and antenna156 can provide the required disablement/destruction functionality ofthe counter IED airborne system. Alternatively, a single transceiver orany desired combination of transceivers (such as a single transceivertaking the place of both the wide beam transmitter 150 and 151 and thenarrow beam antenna 152 and receiver 153, but still using the separatehigh power microwave burst transmitter 155 and antenna 156) can be used.That is, any desired combination of transmitters and receivers can beused to provide for the transmission and/or reception of the wide beam,narrow beam and burst radio frequencies.

Further, the transmitters and receivers can either have a commonantenna, each can have a dedicated antenna, or any desired combinationof shared and dedicated antennas can be used. The antennas can be dishantennas, phased array antennas, or many other types of antennas. Forexample, wide beam transmitter 150 and antenna 151 and narrow beamantenna 152 and receiver 153 can use a shared phased array antenna tofacilitate electronic beam steering and high power microwave burstantenna 156 can use a dish antenna for better power handling.

The frequencies of transmitters 150 and 155 can be selected such thatthey are effective in detecting, locating and disabling or destroyingIEDs. These microwave frequencies of operation can be established bylaboratory/field testing of likely IED systems. Microwave signalfrequencies tend to have advantages in their directionality and in theirability to couple to the non-linear electronic components of IEDs as aresult of high effective radiated power levels that are available inthis frequency region.

High power microwave transmitters 150 and 156, and/or high power bursttransmitter 185 can be variations of Airborne Active ElectronicallyScanned Arrays (AESA) such as the APG-79. Alternatively, thesetransmitters can be custom transmitters or any combination ofcontemporary transmitters, variations or modifications of existingtransmitters, or custom transmitters.

A controller 157 can be used to point the wide beam transmit antenna151, the narrow beam receive antenna 152 and/or high power microwavetransmit antenna 156. Controller 157 can either use a general purposecomputer or a custom controller. Alternatively, wide beam transmitter150, narrow beam receiver 152 and/or high power microwave transmitter156 can be manually controlled.

Controller 157 will set detection transmitter 150's waveform, powerlevel, its duty cycle and the effective radiated power emitted from itswide beam antenna 151. Controller 157 will set disablement bursttransmitter 155's power level, its waveform, its duty cycle/burstduration and the effective radiated power emitted from its narrow beamantenna 156. Controller 157 will also set select receiver 153'sfrequency range, bandwidth and scan parameters as well as narrow beamreceiver antenna 152's pointing angles and scan parameters

Thus, once detected, the presence of an IED can be verified. Onceverified, its location can be more precisely defined. Then, the IED canbe rendered ineffective by directing a burst of high power microwaveradiation, such as via a narrow beam thereof, at the IED. Additionally,the IED can alternately be rendered ineffective by one or more means byusing gunfire against it, such as with a gun mounted upon an airbornevehicle; by dropping ordinance upon it from an airborne vehicle; or byconventional explosive ordnance disposal methods (such as disarming anddisposing of the IED or by detonating it in place with additionalexplosives).

FIG. 6 is a flow chart illustrating operation of an exemplary embodimentof an IED countermeasures system of the present invention, such as thatshown in FIG. 5. A signal containing two or more frequencies of highpower microwave radiation is directed toward a suspect area, such asalong roadway 13 of FIGS. 1-3. This can be performed with wide beam,dual band, high power microwave transmitter 150 and transmit antenna151. This process can continue until an IED is illuminated, as indicatedin block 61.

When an IED is illuminated with the two frequencies of high powermicrowave radiation, the non-linear components thereof can re-radiateelectromagnetic radiation, as described above. When such re-radiationoccurs, the frequency-shifted return can be detected. If no return isdetected (such as when no IED is being illuminated), the process ofillumination can continue, as indicated by decision block 62.

When a return is detected, the return can be verified as indicated byblock 63. Verification can be performed by comparing the return to adatabase of known IED re-radiation signatures. That is, a signalcomparison process can be implemented to match the spectrum and relativeamplitudes of the re-radiated RF return compared to those stored in thedatabase. A match can indicate a high probability that the return isfrom an IED.

If the return is not verified, the illumination of the suspect area withwide beam high power microwave radiation can continue, as indicated bydecision block 64. If the return is verified as likely being from anIED, then narrow beam dual band high power microwave radiation can beused to better determine the position of the IED, as indicated in block64. This process can be performed with narrow beam antenna 152 andreceiver 153.

Higher frequency microwave radiation can be used in the locationprocess. As those skilled in the art understand, the use of higherfrequency microwave radiation facilitates the use of a narrower beam. Anarrowed beam provides more focused reception such that when a return isreceived, the possible locations where the IED can be disposed are morelimited.

Once the location of the IED has been determined, then a burst of narrowbeam, high power microwave radiation can be directed to the IED so as todisable or destroy it, as indicated in block 66. Alternatively, othermethods for disabling or destroying the IED can be employed. Forexample, gunfire or explosive ordnance can be used to render the IEDineffective, as discussed above.

According to one or more embodiments of the present invention, IEDs,even partially buried IEDS, can be found and rendered ineffective. IEDscan be detected with few false positive indications. Detection, locationand disablement or destruction can all be performed from a platform thatis far enough away form the IED so as to be safe, i.e., substantiallyunaffected by an explosion of the device.

The risks associated with the use of surface vehicles, such as thevehicles in convoy 14 of FIGS. 1-3, are substantially mitigated. Therisks associated with explosives ordnance disposal are also mitigated.Thus, one or more embodiments of the present invention provide a robustsystem for mitigating the risks associated with IEDs.

Embodiments described above illustrate but do not limit the invention.It should also be understood that numerous modifications and variationsare possible in accordance with the principles of the present invention.Accordingly, the scope of the invention is defined only by the followingclaims.

1. A method for mitigating effectiveness of an improvised explosivedevice (IED), the method comprising: detecting a presence of the IED bydetecting a presence of a non-linear electronic component of the IED,wherein detecting the presence of the non-linear component of the IEDcomprises: illuminating the IED with a first signal containing a firstplurality of frequencies and having a comparatively wide beam, andreceiving a first complex signal return including at least one of sum ordifference frequencies or harmonics produced by interaction of the firstsignal with one or more of the LED's non-linear components; in responseto detecting the presence of the IED, verifying the presence of the IEDby determining whether a signature of the first complex signal return isconsistent with expected IED signatures; in response to verifying thepresence of the IED, determining a location of the IED by: illuminatingthe IED with a second signal containing a second plurality offrequencies and having a comparatively narrow beam, receiving a secondcomplex signal return including at least one of sum or differencefrequencies or harmonics produced by interaction of the second signalwith one or more of the IED's non-linear components, wherein the secondplurality of frequencies are higher than the first plurality offrequencies, and determining a round-trip propagation time of the secondsignal and the second complex signal return; and in response todetermining the location of the IED, disabling the IED by directing aburst of electromagnetic radiation to the determined location of theIED.
 2. The method of claim 1, wherein the frequencies of the firstsignal comprise at least two frequencies of microwave radiation.
 3. Themethod of claim 1, wherein the verifying comprises comparing at leastone of sum or difference frequencies or harmonics of the first complexsignal with stored signature data in order to confirm detection of theIED.
 4. The method of claim 1, wherein the frequencies of the secondsignal comprise at least two frequencies of microwave radiation, whereinthe second signal is transmitted by a narrow beam antenna.
 5. The methodof claim 1, wherein the second complex signal is a microwave signal,wherein the receiving the second complex signal is performed using anarrow receive beam.
 6. The method of claim 1, wherein the receiving thesecond complex signal comprises receiving microwave re-radiated energy,wherein the determining the location of the IED comprises using ahighest available frequency component of the re-radiated energy.
 7. Themethod of claim 1, wherein the disabling the IED comprises illuminatingthe IED with a burst of comparatively higher power microwave radiationusing a comparatively narrow beam antenna.
 8. A system for mitigatingeffectiveness of an improvised explosive device (IED), the systemcomprising: a first transmitter and a first transmit antenna forilluminating the IED with a first signal containing a first plurality offrequencies and having a comparatively wide beam; a first receiver and afirst receive antenna for receiving a first complex signal returnincluding at least one of sum or difference frequencies or harmonicsproduced by interaction of the first signal with one or more of theIED's non-linear components to detect a presence of the IED; a detectionverification system for verifying a presence of the IED in response tothe detected presence of the IED based on whether a signature of thefirst complex signal return is consistent with expected IED signatures;a second transmitter and a second transmit antenna for illuminating theIED with a second signal containing a second plurality of frequenciesand having a comparatively narrow beam; a second receiver and a secondreceive antenna for receiving a second complex signal return includingat least one of sum or difference frequencies or harmonics produced byinteraction of the second signal with one or more of the IED'snon-linear components to determine a round-trip propagation time of thesecond signal and the second complex signal return and a location of theIED in response to the verified presence of the IED, wherein the secondplurality of frequencies are higher than the first plurality offrequencies; and a third transmitter and a third transmit antenna fordisabling the IED in response to the determined location of the IED bydirecting a burst of electromagnetic radiation to the determinedlocation of the IED.
 9. The system of claim 8, wherein the firsttransmitter is a microwave transmitter.
 10. The system of claim 8,wherein the first transmitter is a dual band microwave transmitter. 11.The system of claim 8, wherein the first transmitter is a high powermicrowave transmitter.
 12. The system of claim 8, wherein the firsttransmitter is a wide beam microwave transmitter.
 13. The system ofclaim 8, wherein the first receiver is tuned to a specific frequencycomponent of a re-radiated signal from the IED.
 14. The system of claim8, wherein the third transmitter is a high power burst transmitter forrendering IEDs ineffective.
 15. The system of claim 8, wherein the thirdtransmitter is a high power microwave burst transmitter for renderingIEDs ineffective.
 16. The system of claim 8, wherein the second antennahas a relatively narrow beam.
 17. The system of claim 8, wherein thefirst antenna has a relatively wide beam.
 18. The system of claim 8,wherein the first, second, and third transmit antennas and the first andsecond receive antennas are dedicated antennas.
 19. The system of claim8, wherein two or more of the first, second, and third transmit antennasand the first and second receive antennas are shared antennas.
 20. Thesystem of claim 8, wherein the first, second, and third transmitters andthe first and second receivers are dedicated transmitters and receivers.21. The system of claim 8, wherein two or more of the first, second, andthird transmitters and the first and second receivers are sharedtransceivers.
 22. A system for locating an improvised explosive device(IED), the system comprising: means for detecting a presence of the IEDby detecting a presence of a non-linear electronic component of the IED,the detecting means comprising: means for illuminating the IED with afirst signal containing a first plurality of frequencies and having acomparatively wide beam, and means for receiving a first complex signalreturn including at least one of sum or difference frequencies orharmonics produced by interaction of the first signal with one or moreof the IED's non-linear components; means for verifying the presence ofthe IED by determining whether a signature of the first complex signalreturn is consistent with expected IED signatures in response to thedetecting means; means for determining a location of the IED in responseto the verifying means, the determining means comprising: means forilluminating the IED with a second signal containing a second pluralityof frequencies and having a comparatively narrow beam, means forreceiving a second complex signal return including at least one of sumor difference frequencies or harmonics produced by interaction of thesecond signal with one or more of the IED's non-linear components,wherein the second plurality of frequencies are higher than the firstplurality of frequencies, and means for determining a round-trippropagation time of the second signal and the second complex signalreturn; and means for disabling the IED by directing a burst ofelectromagnetic radiation to the determined location of the IED inresponse to the determining means.